The invention relates to a perforating munition for targets possessing high mechanical strength.
Perforating munitions used, for example, against concrete runways are generally placed in an air vehicle, called a carrier, that has to fly over the target at very low altitude and very high speed. To avert the risk of the destruction of the air vehicle by enemy ground-air defenses, this vehicle has an altitude of the order of 75 m and a speed of the order of 300 m/s. At an instant determined so that the desired objective is reached, the air vehicle ejects the different munitions with high horizontal velocity and in a horizontal attitude parallel to the plane containing the target as shown in FIG. 1. Each munition M, at the end of its trajectory, at impact I, should have a velocity vector that is as close as possible to the vertical in order to facilitate the complete penetration of the munition into the target before the final explosion. The munition therefore has an incidence defined as the angle between the vector of velocity with respect to the target and the vertical to the target placed horizontally. To this end, each munition has a braking phase F and an acceleration phase A by which the munition is respectively given an orientation and a velocity necessary for a perforating munition to function in order to damage a concrete runway. The phase of acceleration of the munition should be triggered at an altitude Z sufficient for the end of the propulsion to take place before impact. It being known that this altitude is determined as a function of a length 1 of the propelled-mode trajectory defined by: ##EQU1## -V.sub.o : velocity of the munition at the end of bracking; -V : velocity of the munition at the end of propulsion;
-T : combustion time of the propellant; PA1 -i : angle of incidence which is the angle between the velocity vector with respect to the target and the vertical of the target placed horizontally;
and that these parameters are determined so as to have, for example, an impact velocity V=350 m/s and a combustion time which, in the present state of the art and in view of the geometrical constraints, cannot be reduced to less than 0.2 s, the length of the propelled-mode trajectory will be about 35 m, i.e. the propulsion has to be ignited at an altitude of at least Z=40 m. Furthermore, at the end of the braking phase F, the munition should have an attitude close to the vertical, for example an incidence i=15.degree., after a ballistic drop equal to the difference between the altitude of release and that of the ignition of the propulsion, i.e. under the conditions chosen here above, the altitude of release being 75 m, there are only 35 m available to obtain the desired attitude. To obtain this result, it is necessary to use a braking system, for example a parachute positioned in the rear of the munition, the dimensions and sturdiness of which would be incompatible with the space available.
There are numerous munitions designed to perforate and damage surfaces possessing high mechanical strength. These munitions, the effectiveness of which depends on a large number of parameters (such as the penetration depth, the quantity of explosive charge etc.) are generally released at very low altitude from an air vehicle possessing dictated dimensions that determine a volume in which the munition has to be housed. Since this air vehicle has a determined size, it limits the number and size of the modules contained inside the perforating module. To provide for the performance characteristics of a munition such as this, it is necessary to position the largest number of modules possible within the munition. To this end, it is therefore necessary to find an architecture of the munition in order to exploit the available space as efficiently as possible.